libsanitizer/tsan/tsan_mman.cc

   1 //===-- tsan_mman.cc ------------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of ThreadSanitizer (TSan), a race detector.
   9 //
  10 //===----------------------------------------------------------------------===//
  11 #include "sanitizer_common/sanitizer_common.h"
  12 #include "sanitizer_common/sanitizer_placement_new.h"
  13 #include "tsan_mman.h"
  14 #include "tsan_rtl.h"
  15 #include "tsan_report.h"
  16 #include "tsan_flags.h"
  17
  18 // May be overriden by front-end.
  19 extern "C" void WEAK __tsan_malloc_hook(void *ptr, uptr size) {
  20   (void)ptr;
  21   (void)size;
  22 }
  23
  24 extern "C" void WEAK __tsan_free_hook(void *ptr) {
  25   (void)ptr;
  26 }
  27
  28 namespace __tsan {
  29
  30 COMPILER_CHECK(sizeof(MBlock) == 16);
  31
  32 void MBlock::Lock() {
  33   atomic_uintptr_t *a = reinterpret_cast<atomic_uintptr_t*>(this);
  34   uptr v = atomic_load(a, memory_order_relaxed);
  35   for (int iter = 0;; iter++) {
  36     if (v & 1) {
  37       if (iter < 10)
  38         proc_yield(20);
  39       else
  40         internal_sched_yield();
  41       v = atomic_load(a, memory_order_relaxed);
  42       continue;
  43     }
  44     if (atomic_compare_exchange_weak(a, &v, v | 1, memory_order_acquire))
  45       break;
  46   }
  47 }
  48
  49 void MBlock::Unlock() {
  50   atomic_uintptr_t *a = reinterpret_cast<atomic_uintptr_t*>(this);
  51   uptr v = atomic_load(a, memory_order_relaxed);
  52   DCHECK(v & 1);
  53   atomic_store(a, v & ~1, memory_order_relaxed);
  54 }
  55
  56 struct MapUnmapCallback {
  57   void OnMap(uptr p, uptr size) const { }
  58   void OnUnmap(uptr p, uptr size) const {
  59     // We are about to unmap a chunk of user memory.
  60     // Mark the corresponding shadow memory as not needed.
  61     DontNeedShadowFor(p, size);
  62   }
  63 };
  64
  65 static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
  66 Allocator *allocator() {
  67   return reinterpret_cast<Allocator*>(&allocator_placeholder);
  68 }
  69
  70 void InitializeAllocator() {
  71   allocator()->Init();
  72 }
  73
  74 void AllocatorThreadStart(ThreadState *thr) {
  75   allocator()->InitCache(&thr->alloc_cache);
  76   internal_allocator()->InitCache(&thr->internal_alloc_cache);
  77 }
  78
  79 void AllocatorThreadFinish(ThreadState *thr) {
  80   allocator()->DestroyCache(&thr->alloc_cache);
  81   internal_allocator()->DestroyCache(&thr->internal_alloc_cache);
  82 }
  83
  84 void AllocatorPrintStats() {
  85   allocator()->PrintStats();
  86 }
  87
  88 static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
  89   if (!thr->in_signal_handler || !flags()->report_signal_unsafe)
  90     return;
  91   StackTrace stack;
  92   stack.ObtainCurrent(thr, pc);
  93   ThreadRegistryLock l(ctx->thread_registry);
  94   ScopedReport rep(ReportTypeSignalUnsafe);
  95   if (!IsFiredSuppression(ctx, rep, stack)) {
  96     rep.AddStack(&stack);
  97     OutputReport(ctx, rep, rep.GetReport()->stacks[0]);
  98   }
  99 }
 100
 101 void *user_alloc(ThreadState *thr, uptr pc, uptr sz, uptr align) {
 102   if ((sz >= (1ull << 40)) || (align >= (1ull << 40)))
 103     return AllocatorReturnNull();
 104   void *p = allocator()->Allocate(&thr->alloc_cache, sz, align);
 105   if (p == 0)
 106     return 0;
 107   MBlock *b = new(allocator()->GetMetaData(p)) MBlock;
 108   b->Init(sz, thr->tid, CurrentStackId(thr, pc));
 109   if (ctx && ctx->initialized) {
 110     if (thr->ignore_reads_and_writes == 0)
 111       MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
 112     else
 113       MemoryResetRange(thr, pc, (uptr)p, sz);
 114   }
 115   DPrintf("#%d: alloc(%zu) = %p\n", thr->tid, sz, p);
 116   SignalUnsafeCall(thr, pc);
 117   return p;
 118 }
 119
 120 void user_free(ThreadState *thr, uptr pc, void *p) {
 121   CHECK_NE(p, (void*)0);
 122   DPrintf("#%d: free(%p)\n", thr->tid, p);
 123   MBlock *b = (MBlock*)allocator()->GetMetaData(p);
 124   if (b->ListHead()) {
 125     MBlock::ScopedLock l(b);
 126     for (SyncVar *s = b->ListHead(); s;) {
 127       SyncVar *res = s;
 128       s = s->next;
 129       StatInc(thr, StatSyncDestroyed);
 130       res->mtx.Lock();
 131       res->mtx.Unlock();
 132       DestroyAndFree(res);
 133     }
 134     b->ListReset();
 135   }
 136   if (ctx && ctx->initialized) {
 137     if (thr->ignore_reads_and_writes == 0)
 138       MemoryRangeFreed(thr, pc, (uptr)p, b->Size());
 139   }
 140   allocator()->Deallocate(&thr->alloc_cache, p);
 141   SignalUnsafeCall(thr, pc);
 142 }
 143
 144 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
 145   void *p2 = 0;
 146   // FIXME: Handle "shrinking" more efficiently,
 147   // it seems that some software actually does this.
 148   if (sz) {
 149     p2 = user_alloc(thr, pc, sz);
 150     if (p2 == 0)
 151       return 0;
 152     if (p) {
 153       MBlock *b = user_mblock(thr, p);
 154       CHECK_NE(b, 0);
 155       internal_memcpy(p2, p, min(b->Size(), sz));
 156     }
 157   }
 158   if (p)
 159     user_free(thr, pc, p);
 160   return p2;
 161 }
 162
 163 uptr user_alloc_usable_size(ThreadState *thr, uptr pc, void *p) {
 164   if (p == 0)
 165     return 0;
 166   MBlock *b = (MBlock*)allocator()->GetMetaData(p);
 167   return b ? b->Size() : 0;
 168 }
 169
 170 MBlock *user_mblock(ThreadState *thr, void *p) {
 171   CHECK_NE(p, 0);
 172   Allocator *a = allocator();
 173   void *b = a->GetBlockBegin(p);
 174   if (b == 0)
 175     return 0;
 176   return (MBlock*)a->GetMetaData(b);
 177 }
 178
 179 void invoke_malloc_hook(void *ptr, uptr size) {
 180   ThreadState *thr = cur_thread();
 181   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 182     return;
 183   __tsan_malloc_hook(ptr, size);
 184 }
 185
 186 void invoke_free_hook(void *ptr) {
 187   ThreadState *thr = cur_thread();
 188   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 189     return;
 190   __tsan_free_hook(ptr);
 191 }
 192
 193 void *internal_alloc(MBlockType typ, uptr sz) {
 194   ThreadState *thr = cur_thread();
 195   CHECK_LE(sz, InternalSizeClassMap::kMaxSize);
 196   if (thr->nomalloc) {
 197     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 198     CHECK(0);
 199   }
 200   return InternalAlloc(sz, &thr->internal_alloc_cache);
 201 }
 202
 203 void internal_free(void *p) {
 204   ThreadState *thr = cur_thread();
 205   if (thr->nomalloc) {
 206     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 207     CHECK(0);
 208   }
 209   InternalFree(p, &thr->internal_alloc_cache);
 210 }
 211
 212 }  // namespace __tsan
 213
 214 using namespace __tsan;
 215
 216 extern "C" {
 217 uptr __tsan_get_current_allocated_bytes() {
 218   uptr stats[AllocatorStatCount];
 219   allocator()->GetStats(stats);
 220   return stats[AllocatorStatAllocated];
 221 }
 222
 223 uptr __tsan_get_heap_size() {
 224   uptr stats[AllocatorStatCount];
 225   allocator()->GetStats(stats);
 226   return stats[AllocatorStatMapped];
 227 }
 228
 229 uptr __tsan_get_free_bytes() {
 230   return 1;
 231 }
 232
 233 uptr __tsan_get_unmapped_bytes() {
 234   return 1;
 235 }
 236
 237 uptr __tsan_get_estimated_allocated_size(uptr size) {
 238   return size;
 239 }
 240
 241 bool __tsan_get_ownership(void *p) {
 242   return allocator()->GetBlockBegin(p) != 0;
 243 }
 244
 245 uptr __tsan_get_allocated_size(void *p) {
 246   if (p == 0)
 247     return 0;
 248   p = allocator()->GetBlockBegin(p);
 249   if (p == 0)
 250     return 0;
 251   MBlock *b = (MBlock*)allocator()->GetMetaData(p);
 252   return b->Size();
 253 }
 254
 255 void __tsan_on_thread_idle() {
 256   ThreadState *thr = cur_thread();
 257   allocator()->SwallowCache(&thr->alloc_cache);
 258   internal_allocator()->SwallowCache(&thr->internal_alloc_cache);
 259 }
 260 }  // extern "C"